Four cross combinations between modern rose cultivars (Rosa hybrida, 2n = 4x = 28), as female
parents, and R. rugosa cultivars (2n = 2x = 14), as male parents, were carried out, and thirteen F1
hybrids were obtained, among which seven hybrids were chosen to be evaluated and identified by
morphological observation, flow cytometry, karyotype analysis and simple sequence repeat ( SSR)
markers. The results showed that F1 hybrids integrated the morphological characteristics of both R.
hybrida and R. rugosa. Both flow cytometry analysis and karyotype analysis showed that the 7 hybrids
were all triploids (2n =3x =21), karyotype parameters of the hybrids were between the female and male
parents. The karyotype of most hybrids was 1A. The results of 11 SSR markers indicated that all of the 7
selected hybrids contained the specific bands of both parents. All the morphological, cytological, and
SSR marker data proved that all hybrids integrated the genetic material and morphological traits of both
modern rose cultivars and R. rugosa cultivars, which provided new germplasm materials for the
improvement of modern rose using R. rugosa. The results also show that flow cytometry analysis can be
used to rapidly identify hybrids whose parents have different ploidy.